Paper indicated loom dobby



` Dec. 15, 1942. w. H. WAKEFILD PAPER INDICATED LOOM DOBBY Filed Jan. 5, 19.42

NvENw-OR. WALT E R H. WAKEHELD HTTORNEY Patented Dec. 15, 1942 UNlTEa STATES, PATENT i OFFICE PAPER; mmsiaoompor Walter H.V Wakefield, Worcester,l Mas-s., assigner Loom Works,l

Worcester, Mass., a corporation of- Massachusetts Application January 5, 1942, Serial No'. 425,611

13' Claims. (Cl. 139-68) This invention relates to improvements in loom dobbies indicated by sheet or paper patterns and it is the general object of the invention to provide a dobby wherein a relatively low grade of paper may be employed for the pattern. f

It has been proposed heretofore to employ paper patterns provided with perforated. and unperforated parts which cooperate with liftingelements for the dobby hooks. In these previousl mechanisms it has been necessary for the paper to withstand all of the force. required to lift'the hook and this condition has necessitated the use of high grade paper.

The force required to lift the dobby hook. may be resolved into three factors, one of which is thev weight of the hook and the second of which is the weight of the hook lifting wire. The upward force which lifts the hook must be supplemented by a third factor constituting a factor of safety to insure positive movement of the hook. It isl an important object of my Vpresent invention to provide a dobby in which the paper pattern need be only strong enough to overcome the third factor already mentioned. This result I accomplish by permitting the unperforated part of the paper to move with the yieldable lifters until their force is partly counterbalanced by the force growing' out of the Weight of the hooks and its lifter wires. In this way the paper is required to withstand only the third of the above mentioned factors and need not be strong enough to withstand a force strong enough to include the first two factors.

In order that the unperforated parts of the paper pattern may be subjected to a minimum amount of force it is another object of my present invention to provide a support or guide for the pattern so proportioned that those parts of the4 paper pattern which are being read for a pattern indication can yield upwardly without: material strain until the lifting plunger establishes force transmitting relation with thehook lifter wire. Thereafter the net upward thrust of the plunger will be equal to the third factor above mentioned, and will be the only force impressed upon the paper, since the totalv force of the yielding lifting plunger has been partly neutralized by the Weight of the hook and its lifter Wire.

With these and other objects in view whichwill appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawing, wherein a convenient embodiment ofl my invention isset forth,-

cording to my present invention, parts being in section and the front' knife operating lever being removed,

Figs. 2 and 3 are diagrammatic views illustratingthe manner of operation of my invention,

Fig. 4 is a plan view looking in the direction of arrow 4, Fig. 2,

Fig'. 5 is a vertical elevation on line 5-5 of Fig. .1, and

@Fig 6 is a view'v of'v one of the lifter units.

vReferring particularly to Fig. 1, I have shown a loom frame l on which is mounted a bracket I Iy which supports the dobby D. The dobby frame I2 supportsa rod I3` on which are mounted the' harness lifting jacks I4. Each jack has a jack lever I pivotedas at I6 and I1 to upper and ylower hooks I8 and I9, respectively. Top and botto-m cross girts and 2|, respectively, serve to limit right hand motion of the jack levers I5l and thusv position the harness jacks I4. Top

I and bottom combs 22 and 23,A respectively, serve to moves inwardly, and on the next pick opposite motion of the-lever causes reverse'motion of the knives The knives are adapted for engagement with the heads 3| formed on the left ends of the hooks when the latter are raised.

) In order that the hoo-ks may be Yraised from their normally down position I provide twovsystems o'f lifter wires. The longer Wires-shown at 35 for. the top hooks extend upwardly through a guide 36V fixed with respect to the dobby frame.

Shorter lifter wires 31 for the bottom hooks are also guided by the plate. The upper ends of the wires. are hooked as at 38 for engagement with their respective combs. Each top hook I8 .will be provided with one of the longer lifter wires. 35 while each of the lower hooks I9 will be lprovided with a shorter wire 31. The bottoms of the wires 35 and 31 project below the guide Y 36, as indicatedin Fig. 1, and their down position is determinedby the combs.

As shown in Fig. 5` a carriage 4t under the Figin 1- is a front'elevation' ofal dobby made a'c- 55' lifterv wires is guided for vertical motion by front and back guide pins 4| and 42, respectively, fixed with respect to the dobby frame. A shaft 43 parallel to and extending horizontally behind the rear of the dobby frame has secured thereto a cam 44 for cooperation with lever 45. The shaft 43 is supported from the dobby and is given a complete rotation every second pick of the loom by mechanism not shown. This timing is in view of the fact that the dobby operates on the so-called double index principle. Lever 45 has a fixed pivot 46 and an arm 41 connected to an upwardly extending link 48 attached as at 48 to the left end of the carriage 40. `A depending arm 50 of lever 45 is connected as at 5| to a link 52 extending forwardly for connection as at 53 to the depending arm 54 of a second lever 55 mounted on a fixed pivot 56. A link 51 extends upwardly from lever 55 and is attached as at 58 to the front end of carriage 40.

The cam is so designed as to raise the carriage 40 either slightly before or at the time the bottom knife is in its extreme right hand position as shown in Fig. 1 and maintain the carriage in raised position for more than a pick of the loom, or until after the time has passed'for indicating the top hooks.

The carriage is provided with two rows of spring plungers B5 shown particularly in Fig. 6. Each plunger has a stem 6| which projects through the bottom horizontal ange 62 of the carriage. A compression spring 63 above the flange surrounds the lower part of each stem and exerts an upward force on 'a shoulder 64 formed on the stem. A stop B5 on each stem is positioned for engagement with the top horizontal flange 65 of the carriage, and each stem extends upwardly from the carriage as indicated in Fig. 1 to a position adjacent to the lower end of the guide and the bottoms of the lifter wires 35 and 31.

The paper pattern 1|) is fed by means of right and left hand cylinders 1| and 12 respectively actuated by worms 13 on shaft 43 meshing with worm wheels 14 on the cylinders to feed them while the carriage is in low position. The paper pattern, as shown in Fig. 4, may be provided with perforations 15 and unperforated areas 18, the perforated and unperforated portions being arranged in pairs of transverse parallel rows, and each pair forming a pattern zone to be read by the plungers. The pattern is advanced every second pick of the loom and the zones move successively to reading position immediately over v the-stems 6|.

Much of the mechanism already described may be the same as set forth in copending application Serial No. 402,080.

In carryingmy present invention into effect, I provide the lower part of the guide 3B with two spaced horizontal plates 8| and 82, respectively which are separated by a space or slot 83 of more width than the space occupied by a zone of the pattern. This .relation is suggested in Fig. 4 where it will be seen that the zone in reading position is located substantially midway between adjacent edges of the plates 8| and 82.

The paper pattern passes under the plates and of relatively low grade paper.

in stationary position While the carriage 40 is raised. At the start of the upward motion of the carriage the upper ends of the stems 6| will be slightly below the bottom of the paper 10, as suggested in Fig. 2, but as the carriage continues to rise certain of the stems 6| will engage unperforated parts of the paper and bend those parts of the paper between bars 8| and 82 upwardly into engagement with the associated lifter wires, as suggested in Fig. 3. The stems 6| which are in register with perforations 15 will pass through the paper to engage the lifter wires aligning with them and as the carriage approaches the upper end of its travel the hooks corresponding to the perforations 15 will be raised into the paths of their knives. The stems 6| which engage unperforated portions of the pattern however will be held in down position so that the corresponding hooks will remain out of the paths of their knives. Upward motion of the carriage causes compression of the springs 63 of those stems 6| which engage the paper. The pattern feeding cylinders will be set in such relative positions as to provide the small amount of slack which permits the upward flexing of the paper sheet suggested in Fig. 3.

In further explanation of the invention it may be assumed that each hook weighs 2.5 ounces, that long wires 35 weigh 0.75 ounce and short wires 0.25 ounce. The downward force exerted by each upper hook |8 and its wire 35 will be 3.25 ounces. Allowing 2 ounces as the third factor already mentioned to insure positive lifting of the hooks, the springs for the plungers 6| which lift wires 35 will be strong enough to transmit a force of 5.25 ounces without yielding, but will yield at slightly higher loads. When the paper bends upwardly as indicated in Fig. 3 the down force of 3.25 ounces will be transmitted through the paper to the stern 6| and the net upward force of the corresponding spring 63 will be 2 ounces. The paper therefore need be no stronger than that needed to withstand a force of 2 ounces plus a moderate safety factor in order to cause compression of the springs 63, and the paper need not be strong enough to withstand the entire force of 5.25 ounces.

The relationship just described with respect to the top hooks exists also with respect to the bottom hooks except that in the latter instance the combined downward force of the hooks and their corresponding short wires 31 is somewhat less than that of the top hooks and the counter-balancing effect on the right hand row of plungers as viewed in Fig. 1 will be less than for the left hand row. This discrepancy may be provided for either by having a paper sufciently strong to tolerate the difference in forces or by using weaker springs on the right hand row of stems. In either instance the paper will not be required to withstand an upward thrustV of the plunger equal to the total force required to lift the bottom hooks.

From the foregoing it will be seen that I have provided simple means for permitting the hooks of a loom dobby to be indicated by patterns made It will be seen that this result is accomplished by permitting a zone of the pattern paper to ex upwardly until the lifting plungers can have a part of their lifting force counter-balanced by the combined weights of the wires aligning with them and the associated hooks. By reason of this relation the paper. is required to withstand only the difference between `the upward forcelof the lifting stems and the' downward forces of thewires and hooks.

It will furtherbe seenV that provision may be Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing' from the spirit and; scope ofl the invention andI do not wish to be limited tothe details herein disclosed, but what I claim is:

1. In a loom dobby having a lifter knife and a harness lifting hook to be moved with respect to they path of the knife by a lifter wire said hook and wirey exerting a given downward force, a paper pattern having perforated and unperforated zones movable to pattern reading position under the lifter wire, guide means for the paper pattern constructed to provide an area of slackness in the paper pattern adjacent to an unperforated zone in pattern reading position and to restrict` upward motion of the paper4 pattern, mechanism to move said zones successively to pattern reading position, a yieldable lifting member aligned with the lifter wire under the paper and yieldable only under a force greater than said given force, and means to move said member against the paperl to lift the latter against the lifter` wire and thereby take said slackness out. of the paper subsequent to movement of an` unperforated part of the paper against said wire by the member, continued upward motion of themember after engagement of the` paperwith said lifter wire causing saidgiven force to be exerted downwardly against the member and cause the latter to exert on saidv paper a force tending to puncture the paper which is only the difference between said greater force; and said given force.

2. In a loom dobby having a lifter knife and a harness lifting hookl to be moved with respectto the path of the knife by a lifter wire, said hook and wire exerting a given downward force, a paper pattern having perforated and unperforated zones movable to pattern reading position under the lifter wire, means to mount said paper fory limitedV motion toward the lifter wirev to engage the latter, a lifter member under the paper resiliently mounted to yield only when subjected to a force greater than said given force, and means to move said member against an unperforated zone of the paper to cause the latter to move against saidlifter wire, said lifter member when causing the paper to engage said lifter wire exerting a force on the paper tending to puncture the paper which is equal to the difference:

between said greater force and said given force.

3. In a loom dobby having a lifter knife and a harnesslifting hook to be moved with respect to the path of the knife by a lifter wire, said hook and wire; exerting a given downward force, a paper pattern having perforated and unperforated zones movable to'pattern reading position under the lifter wire, spaced guides overA said paper pattern, one on each side of an unperforated zone in pattern reading position, means cooperating with said guides to produce sufficient slack in said paper to permit said zone to be moved upwardly into engagement with the lifter wire and thereby take slackness out of the paper, a lifter member under the paper, means to mount the lifter member resiliently so that said member will yield only'when subjected to a force lgreater, than, saidv given force, and mechanism to move said mounting vmeans and member towards the paper to causeV said lifterV member to move the paper against the. lifter wire, whereby the force exerted by the lifter member on the paper tending to puncture the paper is equal to the difference between said greater force and said given force.

4. In a, loom dobby having a lifter knife and a harness lifting, hook to be moved with respect tothe path of the knife by a lifter wire, said hook and wire exerting, a given downward force, a resiliently mounted lifter member movable toward thelifter wirekand yieldable only to a force greater than said given force, and a paper pattern having an unperforated zone, means to move said zone to pattern reading position between the lifter wire and the lifter member, said zone to be moved by the lifter member against the lifter wire during a pattern reading operation of the dobby and said moving means thereafter preventing further movement of said zone toward the lifter wire, whereby the paper is subjected to a force tending to puncture the paper equal to the difference between said greater force and said given force.

5. In a loom dobbyhaving a lifter knife and a harness liftinghook to be'moved with respect to thepath of the knife by a lifter wire, said hook and Wire exerting a given downward force, a paper pattern having an unperforated zone movable to pattern reading'k Position under the lifter wire, a resilient lifter member movable against said zone to move the latter into engagement with said lifter wire, and means to thereafter prevent further movement of the Zone toward said lifter wire, said lifterv member being yieldable only under a force greater than said given force, said paper pattern being located between the lifterrmember and the lifter wire andv being moved against the latterv by the lifter member when thedobby has a pattern reading operation to cause said given force to be transmitted through the paper against the lifter member to counter-balanceA part of the force required to cause yieldingV of said lifter; member, whereby the paper isy subjected to a deforming force tending to puncture the paper equal to the difference between said greater force and said given force.

6. Inv a loom dobby having a lifter knife and a harness liftingk hookv to be moved with respect to thev path of the knife by a lifter wire, said hook and wire exertingl a given downward force, a paper pattern having perforated and unperforated zones movable to pattern reading position under the lifter wire, a lifter member movable from a position below said paper toward the lifter wire and yieldable, only under a force greater than saidgiven force to cause raising of a lifter wire and hook when said lifter member passes througha perforated part'of said pattern paper, an unperforated part of said pattern paper being moved by the lifter member into engagement with the lifter wire whereby said given force partly counter-balances the force required to cause yielding of the lifter member, and means td thereafter, prevent. further motion of said unperforated zone in a direction toward said lifter wire, whereby the paper is required to withstand a force tending to puncture the paper equal only to the difference between said greater and said given forces.

7. In a loom dobby having a lifter knife and a harness lifting hook to be moved with respect to the path `of the knife by a lifter wire, said hook and wire exerting a given downward force, a paper pattern having perforated and unperforated zones movable to pattern reading position under the lifter wire, feeding mechanism to move said Zones progressively to pattern reading position and create limited slackness in said paper pattern, a yieldable lifter member under the pattern in alignment with the lifter wire and a zone in pattern reading position and yieldable only under a force greater than said given force, and means to move said lifter member against an unperforated zone to lift the latter into-engagement with the lifter wire and take up said lim-v ited slackness and thereby cause said given force to counteract part of the force required to cause yielding of the lifter member, whereby the unperforated Zone is required to withstand only that force tending to puncture the paper which is represented by the difference between said greater and said given forces. l 8. In a loom dobby having a lifter knife an a harness lifting hook to be moved with respect to the path cf the knife by a lifter wire, said hook and wire exerting a given downward force, a paper pattern having perforated and unperforated Zones movable to pattern reading position under the lifter wire, a lifter member mounted under the paper pattern in alignment with a l zone in pattern reading position and the lifter wire and yieldable only under a force greater than said given force, and means to control said paper pattern to cause a limited slackness therein adjacent to said Zone to enable said lifter member to move an unperforated zone in reading position against the lifter wire, after which the paper becomes taut and transmits said given force downwardly against said lifter member to counter-balance a part of the force required toV cause yielding of said lifter member.

9. In a loom dobby having a lifter knife and a harness lifting hook to be moved with respect to the path of the knife by a lifter wire, said hook and wire exerting a given downward force, a paper pattern having perforated and unperforated zones movable to pattern reading position under the lifter wire, a lifter member mounted below the paper and in alignment with the lifter wire and an unperforated zone in pattern reading position,l

means to move the lifter member toward said unperforated zone and lifter wire, and control means for the paper pattern to produce therein a degree of slackness which is taken up to cause the paper to be taut when the lifter member is moved by said means against the unperforated portion and move the latter into engagement with the llifter wire, and a resilient mounting on said means to permit yielding of the lifter member only under a force greater than said given force, whereby the lifter member takes up slackness in the paper when raised by said means and said given force is exerted downwardly through an unperforated portion of the paper in pattern reading position and acts partly to counterbalance the force exerted by said resilient means. Y

10. In a loom dobby having a lifter knife and a harness lifting hook to be moved with respect to the path of the knife by a lifter wire, said hook and wire exertinga given-downward force,V a re- Vsiliently mounted lifter member movable toward in said paper which is taken up when said unperforated zone engages the lifter wire, and means to move said lifter member against the unperforated zone and move the latter against said lifter wire, whereby said unperforated zone is subjected to a force tending to puncture the paper equal only'to the difference between said given force and said greater force. y Y

11. In a loom dobby having a lifter knife and a harness lifting hook to be moved with respect to the knife by a lifter wire, said hook and wire exerting a given downward force, a resilient lifter member under the lifter wire yieldable only under a force greater than said given force, a paper pattern having perforated and unperforated zones, feed cylinders to move said paper pattern to place the perforated and unperforated zones between said lifter wire and said lifter member and create in said paper pattern a slackness, guide means for the paper pattern located between the feed cylinders and above the paper pattern and positioned to cause the slackness of said paper pattern to be taken up when an unperforated zone engages the lifter wire, and means to move the lifter wire against an unperforated zone to move the latter against the lifter wire, whereby the unperforated Zone transmits said given force downwardly against the lifter member and the latter exerts on said unperforated zone a force tending to puncture the paper equal only tothe difference between the given and the greater forces.

12. The method of controlling the vertical position of a dobby hook and lifter wire therefor which jointly exert a given downward force, said method consisting of the following steps: feeding an unperforated part of a slack paper pattern under the lifter wire, exerting a force greater than said given force upwardly against the unperforated portion of the paper to move the latter against the lifter wire, thereafter preventing further upward motion of said unperforated part, causing the net force exerted against the paper tending to puncture the paper thus to be equal to the difference between said given and said greater forces.

13. The method of controlling the vertical position of a dobby hook and lifter wire therefor which jointly exert a given downward force, said method consisting of the following steps: locating an unperforated portion of a paper pattern under the lifter wire and spaced therebelow, exerting an upward force greater than said given force on the paper to move the latter against the lifter wire to cause the paper to transmit said given force against said greater force, and thereafter holding the paper taut to prevent communication of force from beneath the paper to the lifter wire, 

